impulse (redirected from ectopic impulse)

impulse, in mechanics: see momentum.

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impulse

1. Physics

a. the product of the average magnitude of a force acting on a body and the time for which it acts

b. the change in the momentum of a body as a result of a force acting upon it for a short period of time

2. Physiol See nerve impulse

3. Electronics a less common word for pulse

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impulse [′im‚pəls]

(mechanics)

The integral of a force over an interval of time.

(metallurgy)

A single pulse or several pulses in welding current used in resistance welding.

(physics)

A pulse which lasts for so short a time that its duration can be thought of as infinitesimal.

(psychology)

A sudden psychogenic urge to act.

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Impulse (mechanics)

The integral of a force over an interval of time. For a force F , the impulse J over the interval from t₀ to t₁ can be written as Eq. (1).

(1) 

The impulse thus represents the product of the time interval and the average force acting during the interval. Impulse is a vector quantity with the units of momentum.

The momentum-impulse relation states that the change in momentum of a mass m over a given time interval equals the impulse of the resultant force acting during that interval. The momentum change can be expressed in terms of the velocities v ₁ and v ₀ at times t₁ and t₀, respectively, giving Eq. (2). (2)  See Impact, Momentum